e us rw ica esea a b s t r a c ta r t i c l e i n f o
Accepted 18 November 2015
Available online xxxx hate (CaSO4) scale andmicrobiological growth accumulation posesmajor problems nt mineral scale depocals are toxic and nonyphosphates are their hich undergo hydrolyo orthophosphate that 2]. Today, biodegradaJournal of Molecular Liquids xxx (2015) xxx–xxx
MOLLIQ-05244; No of Pages 11
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Journal of Mole j ourna l homepage: www.e lsstances in these systems coupled with elevated water temperature cause mineral deposition (scaling), corrosion and biofouling. Biofouling bymicrobiological growth causes several operating problems including corrosion, odour and environmental pollution, and purity and quality in the cooling water system. In the case of industrial wastewater, and antiscalants have been widely used to preve sition. Among these, polyphosphate based chemi degradable. Widely noted disadvantages of pol susceptibility, particularly the polyphosphates w sis reactions in aqueous solution and reversion t cause secondary pollutant in the water system [1. Introduction
Most industrial water generally contains suspended solids, organic compounds, microorganisms, dissolved salts (ions) and gasses, high concentrations of calcium, sulphate and bicarbonate ions . These substances escalate the operational and maintenance costs of recirculating cooling water plants. The elevated concentrations of the dissolved subsuspended solids and microorganisms have an adverse effect on the human health and cooling water plant systems as well. These above interrelated problems classified into four categories: scales, corrosion, biofouling (slime and sludge) and microbial growth and accumulation.
Control over the four problems is necessary for maintaining the system in good health. The control of scale deposition through chemical addition has been extensively studied. Various types of inhibition chemicals⁎ Correspondence to: A. Maity, Department of Civ
University of South Africa (UNISA), South Africa. ⁎⁎ Correspondence to: V.K. Gupta, Department of C
Technology Roorkee, Roorkee 247667, India.
E-mail addresses: email@example.com, maityarjun@gma firstname.lastname@example.org (V.K. Gupta). http://dx.doi.org/10.1016/j.molliq.2015.11.034 0167-7322/© 2015 Elsevier B.V. All rights reserved.
Please cite this article as: M.K. Nayunigari, e applications in industrial cooling water treatorminimize these problems, new types of green copolymers, poly(curcumin–malic acid) was specially designed and developed frommalic acid and curcumin. The structural, chemical and thermal properties of the copolymers were analysed using SEM/EDX, FTIR, UV–Vis, X-ray diffraction, TGA and GPC. The scale inhibition efficiency for
CaSO4 scale was investigated by using the static experiment method. The copolymer showed moderate to high sulphate scale inhibition activities based on the amount of curcumin used during copolymerization. The results revealed that due to high molecular weight, the efficiency of the poly(curcumin–malic acid)6 was N95% at 10mg/L dosagewhereas poly(malic acid) (homopolymer) efficiencywas 35.5% at 10mg/L. Hence, it may be reasonably concluded that poly(curcumin–malic acid)6 is a highly effective CaSO4 scale inhibitor for industrial cooling water treatment applications. In addition, the developed copolymers possess a broad antibacterial activity against Escherichia coli and may be useful as antibacterial agents in the industrial cooling water treatment plants. © 2015 Elsevier B.V. All rights reserved.Keywords:
High molecular weight
Water treatmentReceived 13 October 2015
Received in revised form 17 November 2015 in coolingwater treatment plants, thereby affecting the performance of this type of equipment. In order to inhibit
Article history: The formation of calcium sulpCurcumin–malic acid based green copolym microbiological growth applications in ind water treatment
Mithil Kumar Nayunigari a, Arjun Maity a,b,⁎, Shilpi Aga a Department of Civil and Chemical Engineering, University of South Africa (UNISA), South Afr b DST/CSIR National Centre for Nanostructured Materials, Council for Scientific and Industrial R c Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247667, India d Department of Applied Chemistry, University of Johannesburg, Johannesburg, South Africail and Chemical Engineering, hemistry, Indian Institute of il.com (A. Maity), t al., Curcumin–malic acid ba ment, J. Mol. Liq. (2015), httprs for control of scale and trial cooling al d, Vinod Kumar Gupta c,d,⁎⁎ rch, Pretoria 0001, South Africa cular Liquids ev ie r .com/ locate /mol l iqtion and environmentally friendly facilities come into prominence for green polymers. Currently, more attention has been given to environmentally benign scale formation inhibitors, the areawhich has attracted several researchers [3–10]. Biodegradable green polymers prepared by direct polycondensation serve as thermally stable polyesters which are used in wastewater treatment applications such as scale inhibitor and inactivation ofmicroorganisms [7,11,12]. The benefit of using direct sed green copolymers for control of scale and microbiological growth ://dx.doi.org/10.1016/j.molliq.2015.11.034 2 M.K. Nayunigari et al. / Journal of Molecular Liquids xxx (2015) xxx–xxxpolycondensation  synthesis such as thermal heating polycondensation has emerged as a potential route to synthesize “green” antiscalants.
Eco-friendly non-toxic aliphatic polyesters biodegradable polymers are excellent candidates for wound healing applications and have being given a lot more attention since the 1960s . Malic acid is an important dicarboxylic organic acid from the industrial prospective which is widely used because of its acidic property, intermolecular hydrogen bonding interactions, non-toxicity, and availability and relatively low cost. It has two carboxylic groups, which can form chelates with many metal cations and is useful in the removal of heavy-metal contaminants in thewastewater treatment processes. Additionally, malic acid a biodegradable monomer derived from naturally occurring grape and other vegetable fruits, displays unique biomedical, polyanionic, chelating, and descaling properties due to the presence of active carboxylic and hydroxyl functional groups. It is a difunctional monomer that enables polymer network formation and is a non-toxic metabolic product of the body (Krebs or citric acid cycle). It can be reacted with a variety of hydroxyl containing monomers to form polyester based network polymers.